Data Versions

This page provides details of the processing and algorithm history for all versions of SMAP data sets. For an explanation of terminology and version naming conventions, refer to the Naming Conventions section of this page.

Jump to:

SMAP instrument operations sometimes result in problematic or missing data. Details of these events are maintained on two master lists:
SMAP On-Orbit Events List for Instrument Data Users
Master List of Bad and Missing Data

    SMAP L1A Radiometer Time-Ordered Parsed Telemetry (SPL1AP)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 1
     
    2015-03-31 (16:28) to 2015-09-09 (21:04) First public data release Beta R11850 2015-07-31
    Version 1
     
    2015-08-02 (17:17) to 2015-10-26 (18:49) No science change. CRID incremented to coincide with release of SPL2SMP V1 Beta and V1 SPL3SMP Beta data. Beta R11920 2015-09-09
    Version 2
     
    2015-03-31 (16:28) to 2015-11-19 (00:46) 

    Changes to this version include:

    • Transitioned to Validated-Stage 2
    • Calibration parameters were adjusted to reduce calibration jumps and drift previously present in the Beta-release; as a result, calibration now meets its less than 0.4 K/month stability back to 31 March 2015
    • Additional bit-error checking was performed on Level-0 instrument telemetry
    Validated-Stage 2 R12170 2015-10-30
    Version 2
     
    2015-12-17 (18:52) to 2016-02-19 (00:41)  No science change. CRID incremented to coincide with changes made for radar and SPL2SMP processing. Validated-Stage 2 R12240 2015-12-16
    Version 2
     
    2016-02-19 (00:41) to 2016-04-21 (05:16) No science change. CRID incremented to coincide with changes made to the radiometer reflector table for SPL1BTB V2 and SPL1CTB V2. Validated-Stage 2 R12241 2016-01-06
    Version 2 2015-11-18 (23:53) to 2016-12-07 (10:36) No science change. CRID incremented to coincide with the Version 3 release of L1B through L3 products.  Validated-Stage 2 R13080 2016-04-21

    Version 2

    2016-12-07 (10:31) to 2017-04-24 (11:00)

    No science change. CRID incremented to coincide with the release of the following: enhanced products, including SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, SPL3FTP_E (Version 1); SPL3FTP (Version 1); and SPL2SMP, SPL3SMP (Version 4). Validated-Stage 2 R14010 2016-12-07

    Version 2

    2017-04-24 (10:56) to 2017-09-06 (16:52)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 2 R15060 2017-04-24
    Version 2

    2017-09-03 (21:36) to 2017-11-14 (23:14)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 2 R15152 2017-09-03
    Version 2 2017-10-26 (12:22) to 2018-01-09 (21:35)

    No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 2 R15180 2017-10-26

    Version 2

    2017-12-10 (17:54) to 2018-03-14 (19:57)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018. Validated-Stage 2 R15181 2018-01-09
    Version 2

    2018-03-14 (15:51) to 2018-06-03 (23:50)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 2

    R15182

    2018-03-14
    Version 2 2018-06-01 (16:52) to 2018-06-14 (15:50) No science change. CRID incremented to coincide with major version update for all L1-L3 SMAP radiometer products with the exception of SPL2SMAP_S. Validated-Stage 2 R16000 2018-06-01
    Version 2 2015-03-31 (16:28) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage 2 R16010 2018-06-06

    SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures (SPL1BTB)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 1 2015-03-31 (16:28) to 2015-09-09 (06:18) First public data release Beta (ReportPDF Icon) R11850 2015-07-31
    Version 1
     
    2015-09-09 (21:00) to 2015-10-26 (15:32) No science change. CRID incremented to coincide with release of SPL2SMP Beta and SPL3SMP Beta data. Beta (ReportPDF Icon) R11920 2015-09-09
    Version 2 2015-10-26 (22:03) to 2015-10-27 (21:54) No science change. CRID incremented to coincide with DOI correction for SPL2SMP and SPL3SMP.  Validated-Stage 1 (ReportPDF Icon) R12160 2015-10-26
    Version 2
     
    2015-03-31 (16:28) to 2015-12-15 (03:37)

    Changes to this version include:

    • Transitioned to Validated-Stage 1
    • Using SPL1BTB V2 data as input, inherited all changes and improvements of the new version
    Validated-Stage 1 (ReportPDF Icon) R12170 2015-10-30
    Version 2
     
    2015-12-17 (18:52) to 2015-12-31 (23:18) No science change. CRID incremented to coincide with changes made for radar and SPL2SMP processing. Validated-Stage 2 (ReportPDF Icon) R12240 2015-12-16
    Version 2
     
    2015-12-31 (23:14) to 2016-04-21 (06:02) Updated the radiometer reflector table to include the expected temperatures for the radome and reflector for 2016. Validated-Stage 2 (ReportPDF Icon) R12241 2016-01-06
    Version 3
     
    2015-03-31 (16:28) to 2016-12-07 (10:36) Changes to this version include:
    • Updated reflector thermal model
    • Reflector emissivity value back to baseline
    • All calibration coefficients updated back to 3/31/15
    • Direct Galaxy quality flag changed: set when s/c nadir > 5 degrees
    • Reflected Sun quality flag changed: set when specular solar theta <15 degrees
    • Sea ice fraction computation implemented
    Validated-Stage 2 (ReportPDF Icon) R13080 2016-04-21
    Version 3

    2016-12-07 (10:31) to 2017-04-24 (08:32)

    No science change. CRID incremented to coincide with the release of the following: enhanced products, including SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, SPL3FTP_E (Version 1); SPL3FTP (Version 1); and SPL2SMP, SPL3SMP (Version 4). Validated-Stage 2 (ReportPDF Icon) R14010 2016-12-07
    Version 3

    2017-04-24 (08:28) to 2017-09-06 (16:52)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 2 (ReportPDF Icon) R15060 2017-04-24
    Version 3

    2017-09-03 (21:36) to 2017-11-14 (23:14)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 2 (ReportPDF Icon) R15152 2017-09-03
    Version 3 2017-10-26 (00:04) to 

    2018-01-09 (21:35)

    No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 2 (ReportPDF Icon) R15180 2017-10-26
    Version 3

    2017-12-10 (17:54) to 2018-03-14 (19:57)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018. Validated-Stage 2 (ReportPDF Icon) R15181 2018-01-09
    Version 3

    2018-03-14 (15:51) to 2018-06-04 (17:04)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 2 (ReportPDF Icon) R15182

    2018-03-14

    Version 4 2015-03-31 (16:28) to 

    2018-06-14 (15:50)

    Changes to this version include:

    • Added procedure to correct brightness temperatures for water/land contamination near coastlines. New data fields for this correction include: footprint_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_surface_corrected, and tb_v_surface_corrected.
    • Improved Level-1 calibration coefficients and reflected galaxy correction. To refine reflected galaxy correction over ocean, NOAA NCEP ocean roughness data have been added (wind_direction_ancillary, wind_speed_ancillary).
    Validated-Stage 2 (ReportPDF Icon) R16000 2018-06-01
    Version 4 2015-03-31 (16:28) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage 2 (ReportPDF Icon) R16010 2018-06-06

    SMAP L1C Radiometer Half-Orbit 36 km EASE-Grid Brightness Temperatures (SPL1CTB)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 1
     
    2015-03-31 (16:29) to 2015-09-09 (21:04) First public data release Beta (ReportPDF Icon) R11850 2015-07-31
    Version 1
     
    2015-08-02 (21:00) to 2015-10-26 (15:32) No science change. CRID incremented to coincide with release of SPL2SMP V1 Beta and SPL3SMP V1 Beta data. Beta (ReportPDF Icon) R11920 2015-09-09
    Version 2 2015-10-27 (07:04) to 2015-10-27 (21:54) No science change. CRID incremented to coincide with DOI correction for SPL2SMP and SPL3SMP.  Validated-Stage 2 (ReportPDF Icon) R12160 2015-10-27
    Version 2
     
    2015-03-31 (16:29) to 2015-12-15 (03:37)

    Changes to this version include:

    • Transitioned to Validated-Stage 2
    • Using SPL1BTB V2 Validated data as input, inherited all changes and improvements of the new version
    Validated-Stage 2 (ReportPDF Icon) R12170 2015-10-30
    Version 2
     
    2015-04-13 (00:41) to 2015-12-31 (23:18) No science change. CRID incremented to coincide with changes made for radar and SPL2SMP processing. Validated-Stage 2 (ReportPDF Icon) R12240 2015-12-16
    Version 2
     
    2015-12-31 (23:14) to 2016-04-21 (06:02) Updated the radiometer reflector table to include the expected temperatures for the radome and reflector for 2016. Validated-Stage 2 (ReportPDF Icon) R12241 2016-01-06
    Version 3
     
    2015-03-31 (16:28) to 2016-12-07 (00:45) Changes to this version include:
    • Uses updated SPL1BTB V3 Validated data as input
    • Updated processing to produce SPL1CTB data files when partial half-orbit input files are present
    Validated-Stage 2 (ReportPDF Icon) R13080 2016-04-21

    Version 3

    2015-03-31 (16:28) to 2017-04-23 (00:32)

    No science change. CRID incremented to coincide with the release of the following: enhanced products, including SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, SPL3FTP_E (Version 1); SPL3FTP (Version 1); and SPL2SMP, SPL3SMP (Version 4). Validated-Stage 2 (ReportPDF Icon) R14010 2016-12-07

    Version 3

    2017-04-23 (00:28) to 2017-09-06 (16:52)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 2 (ReportPDF Icon) R15060 2017-04-24
    Version 3

    2017-09-03 (21:36) to 2017-11-14 (23:14)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 2 (ReportPDF Icon) R15152

    2017-09-03

    Version 3 2017-10-26 (00:04) to 2018-01-08 (23:26) No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 2 (ReportPDF Icon) R15180 2017-10-26
    Version 3 2017-12-10 (17:54) to 2018-03-14 (19:57)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018.

    Validated-Stage 2 (ReportPDF Icon) R15181 2018-01-09
    Version 3 2018-03-14 (15:58) to 

    2018-06-04 (17:04)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 2 (ReportPDF Icon) R15182 2018-03-14
    Version 4 2015-03-31 (16:28) to 

    2018-06-14 (15:50)

    Updated input SPL1BTB product with water correction applied, resulting in warmer TBs over land and cooler TBs over water. Validated-Stage 2 (ReportPDF Icon) R16000 2018-06-01
    Version 4 2015-03-31 (16:28) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage 2 (ReportPDF Icon) R16010 2018-06-06

    SMAP Enhanced L1C Radiometer Half-Orbit 9 km EASE-Grid Brightness Temperatures (SPL1CTB_E)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented

    Version 1

    2015-03-31 (16:28) to 2017-04-24 (00:20)

    First public data release Validated-Stage1 (ReportPDF Icon) R14010

    2016-12-07

    Version 1

    2017-04-24 (00:16) to 2017-09-06 (16:52)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage1 (ReportPDF Icon) R15060

    2017-04-24

    Version 1

    2017-09-03 (21:36) to 2017-11-14 (23:14)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage1 (ReportPDF Icon) R15152 2017-09-03
    Version 1 2017-10-26 (00:04) to 

    2018-01-08 (23:26)

    No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage1 (ReportPDF Icon) R15180

    2017-10-26

    Version 1 2017-12-10 (17:54) to 2018-03-14 (19:57)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018.

    Validated-Stage1 (ReportPDF Icon) R15181 2018-01-09
    Version 1 2018-03-14 (15:58) to 

    2018-06-04 (17:04)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage1 (ReportPDF Icon) R15182 2018-03-14
    Version 2

    2015-03-31 (16:28) to 2018-06-14 (13:22)

    Updated input SPL1BTB product with water correction applied, resulting in warmer TBs over land and cooler TBs over water. Validated-Stage1 (ReportPDF Icon) R16000 2018-06-01
    Version 2 2015-03-31 (16:28) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage1 (ReportPDF Icon) R16010 2018-06-06

    SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture (SPL2SMP)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 1
     
    2015-09-09 (21:49) to 2015-10-25 (18:12) First public data release Beta (ReportPDF Icon) R11920 2015-09-09
    Version 2
     
    2015-03-31 (17:18) to 2015-12-15 (03:37)

    Changes to this version include:

    • Uses SPL1CTB V2 Validated-Stage 1 data as input
    • Corrects the retrieval quality flag error
    Beta (ReportPDF Icon) R12170 2015-10-30
    Version 2
     

    2015-04-13 (00:41) to 2015-12-31 (23:18)

    Changes to input data processing to use the previous day's snow file if the current day is not available. Beta (ReportPDF Icon) R12240 2015-12-16
    Version 2
     
    2015-08-11 (00:03) to 2016-04-21 (03:38) No science change. CRID incremented to coincide with an update to the radiometer reflector table SPL1BTB V2 and SPL1CTB V2. Beta (ReportPDF Icon) R12241 2016-01-06
    Version 3
     

    2015-03-31 (16:28) to 2016-12-07 (05:40)

    Changes to this version include:

    • Transitioned to Validated-Stage 2
    • Uses updated SPL1CTB V3 Validated data as input
    Validated-Stage 2
    (ReportPDF Icon)
    R13080 2016-04-21
    Version 4
     

    2015-03-31 (16:28) to 2017-04-23 (00:32)

    Changes to this version include:

    • Added 6:00 p.m. ascending half orbits, which provide:
      • More frequent regional/global coverage (critical in flood monitoring)
      • Soil moisture diurnal variability information (useful in data assimilation systems)
      • Consistency with other similar satellite-based soil moisture products
    • Contains frozen ground flag (bit 7 of surface_flag) derived using Normalized Polarization Ration (NPR)-based SMAP passive freeze-thaw retrieval; replaces former SMAP radar-based freeze/thaw flag
    Validated-Stage 3 (ReportPDF Icon)
     
    R14010 2016-12-07
    Version 4

    2017-04-23 (00:28) to 2017-09-01 (23:39)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 3 (ReportPDF Icon) R15060 2017-04-24
    Version 4

    2017-09-02 (00:28) to 2017-10-25 (23:14)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 3 (ReportPDF Icon) R15152

    2017-09-02

    Version 4 2017-10-26 (00:04) to 

    2018-01-08 (23:26)

    No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 3 (ReportPDF Icon) R15180 2017-10-26
    Version 4 2017-12-10 (17:54) to 2018-03-14 (07:39)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018.

    Validated-Stage 3 (ReportPDF Icon) R15181 2018-01-09
    Version 4 2018-03-14 (15:58) to 2018-06-04 (13:47) No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 3 (ReportPDF Icon) R15182 2018-03-14
    Version 5 2015-03-31 (16:28) to 

    2018-06-14 (07:38)

    Changes to this version include:

    • Level-1B water-corrected brightness temperatures are used in passive soil moisture retrieval. This procedure corrects for anomalous soil moisture values seen near coastlines in the previous version and should result in less rejected data due to waterbody contamination. Five new data fields accommodate this correction: grid_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_uncorrected, and tb_v_uncorrected.
    • Improved depth correction for effective soil temperature used in passive soil moisture retrieval; new results are captured in the surface_temperature data field. This correction reduces the dry bias seen when comparing SMAP data to in situ data from the core validation sites.
    • Frozen ground flag updated to reflect improved freeze/thaw detection algorithm, providing better accuracy; new results are captured in bit 7 of the surface_flag.

    Validated-Stage 3 (ReportPDF Icon) R16000 2018-06-01
    Version 5 2015-03-31 (16:28) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage 3 (ReportPDF Icon) R16010 2018-06-06

    SMAP Enhanced L2 Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture (SPL2SMP_E)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented

    Version 1

    2015-03-31 (16:28) to 2017-04-22 (23:43)

    First public data release Validated-Stage 3 (ReportPDF Icon) R14010 2016-12-07

    Version 1

    2017-04-22 (23:39) to 2017-09-05 (23:39)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 3 (ReportPDF Icon) R15060

    2017-04-24

    Version 1

    2017-09-03 (00:16) to 2017-10-25 (23:14)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 3 (ReportPDF Icon) R15152

    2017-09-03

    Version 1 2017-10-26 (00:04) to 2018-01-08 (23:26) No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 3 (ReportPDF Icon) R15180 2017-10-26
    Version 1 2017-12-10 (17:54) to 2018-03-14 (07:39) No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018. Validated-Stage 3 (ReportPDF Icon) R15181 2018-01-09
    Version 1 2018-03-14 (15:58) to 

    2018-06-04 (13:47)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 3 (ReportPDF Icon) R15182 2018-03-14
    Version 2

    2015-03-31 (16:28) to 2018-06-14 (07:38)

    Changes to this version include:

    • Level-1B water-corrected brightness temperatures are used in passive soil moisture retrieval. This procedure corrects for anomalous soil moisture values seen near coastlines in the previous version and should result in less rejected data due to waterbody contamination. Five new data fields accommodate this correction: grid_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_uncorrected, and tb_v_uncorrected.
    • Improved depth correction for effective soil temperature used in passive soil moisture retrieval; new results are captured in the surface_temperature data field. This correction reduces the dry bias seen when comparing SMAP data to in situ data from the core validation sites.
    • Frozen ground flag updated to reflect improved freeze/thaw detection algorithm, providing better accuracy; new results are captured in bit 7 of the surface_flag.

    Validated-Stage 3 (ReportPDF Icon) R16000 2018-06-01
    Version 2 2015-03-31 (16:28) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage 3 (ReportPDF Icon) R16010 2018-06-06

    SMAP L2 Radar Half-Orbit 3 km EASE-Grid Soil Moisture (SPL2SMA)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 2
     
    2015-04-24 (17:19) to 2015-07-08 (00:19) First public data release Beta (ReportPDF Icon) R12170 2015-11-03
    Version 2
     
    2015-04-13 (00:42) to 2015-04-24 (16:32)

    This version incorporates a radar calibration update to process data for 13-23 April 2015.

    Beta (ReportPDF Icon) R12240 2016-01-13
    Version 3
     
    2015-04-13 (18:45) to 2015-07-07 (20:11) Changes to this version include:
    • Transitioned to Validated-Stage 1
    • Uses updated SPL1CS0 V3 as input
    • Updates to some of the data cubes
    • Update of crop database
    • Modified iterative bias correction
    • Estimation of VWC
    Validated-Stage 1 (ReportPDF Icon) R13080

    2016-04-21


    SMAP L2 Radar/Radiometer Half-Orbit 9 km EASE-Grid Soil Moisture (SPL2SMAP)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 2
     
    2015-04-24 (17:18) to 2015-07-07 (00:20) First public data release Beta (ReportPDF Icon) R12170 2015-11-03
    Version 2
     
    2015-04-13 (00:41) to 2015-04-24 (16:33)

    This version incorporates a radar calibration update to process data for 13-23 April 2015

    Beta (ReportPDF Icon) R12240 2016-01-13
    Version 2 2015-04-29 (03:58) to 2015-04-29 (04:51) No science change. CRID incremented to coincide with an update to the radiometer reflector table SPL1BTB V2 and SPL1CTB V2. Beta (ReportPDF Icon) R12241 2016-04-29
    Version 3
     
    2015-04-13 (18:44) to 2015-07-07 (20:10) Changes to this version include:
    • Transitioned to Validated-Stage 2
    • Uses SPL2SMA V3 Validated and SPL2SMP V3 Validated as input
    • Snapshot beta parameter estimation
    • Updated soil texture files (renormalized cases where sand+clay > 100%)
    • Updated default beta parameter
    Validated-Stage 2 (ReportPDF Icon) R13080

    2016-04-21

    SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 1
     
    2015-04-01 (00:00) to 2018-01-08 (00:00) First public data release Beta (ReportPDF Icon) R15180 2017-10-27
    Version 1 2017-12-28 (00:00) to 2018-03-13 (00:00)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018.

    Beta (ReportPDF Icon) R15181 2018-01-09
    Version 1 2018-03-13 (00:00) to 

    2018-06-03 (00:00)

     
    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Beta (ReportPDF Icon) R15182 2018-03-14
    Version 2 2015-04-01 (00:00) to present

    Changes to this version include:

    • Implemented a new method of identifying and eliminating spurious sigma0 values in Sentinel-1A/B Level-1 sigma0 data using a hybrid approach that combines a median filter with thresholding. As a result, fewer spurious sigma0 values (mainly due to small man-made structures) bias the aggregated 1 km data.
    • Replaced the previous 3 km resolution urban fraction map with a new 1 km map.
    • Adjusted the thresholds used with the new 1 km urban fraction map to: 0.25 (no flag), 0.25 – 0.5 (flagged, retrieval performed), and 0.5 (masked, no retrieval). These are provided in bit 3 of the surface_flag data field.
    • Adjusted the tau-omega parameters to be consistent with the values used in SPL2SMP/SPL2SMP_E algorithm.
    • Implemented minor bug fix to the SMAP and Sentinel-1 overlap computation code.
    Beta (ReportPDF Icon) R16010 2018-06-18

    SMAP L3 Radiometer Global Daily 36 km EASE-Grid Soil Moisture (SPL3SMP)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 1
     
    2015-09-10 (00:00) to 2015-10-24 (23:59) First public data release Beta (ReportPDF Icon) R11920 2015-09-09
    Version 2
     
    2015-03-31 (00:00) to 2015-12-15 (23:59)

    Changes to this version include:

    • Uses updated SPL1CTB SPL2SMP V2 Beta data as input
    • Corrects the retrieval quality flag error
    Beta (ReportPDF Icon) R12170 2015-10-30
    Version 2
     
    2015-04-13 (00:00) to 2015-12-31 (23:59) Change to the SPL2SMP V2 input data to use the previous day's snow file if the current day is not available. Beta (ReportPDF Icon) R12240 2015-12-16
    Version 2
     
    2016-01-01 (00:00) to 2016-04-20 (23:59) No science change. CRID incremented to coincide with an update to the radiometer reflector table SPL1BTB V2 and SPL1CTB V2. Beta (ReportPDF Icon) R12241 2015-01-06
    Version 3
     
    2015-03-31 (00:00) to 2016-12-06 (23:59) Changes to this version include:
    • Transitioned to Validated-Stage 2
    • Uses updated SPL2SMP V3 Validated data as input version
    Validated-Stage 2
    (ReportPDF Icon)
    R13080 2016-04-21
    Version 4
     
    2015-03-31 (00:00) to 2017-04-23 (23:59)

    Changes to this version include:

    • Added 6:00 p.m. ascending half orbits, which provide:
      • More frequent regional/global coverage (critical in flood monitoring)
      • Soil moisture diurnal variability information (useful in data assimilation systems)
      • Consistency with other similar satellite-based soil moisture products
    • Contains frozen ground flag (bit 7 of surface_flag) derived using Normalized Polarization Ration (NPR)-based SMAP passive freeze-thaw retrieval; replaces former SMAP radar-based freeze/thaw flag
    Validated-Stage 3 (ReportPDF Icon)
     
    R14010 2016-12-07

    Version 4

    2017-04-23 (00:00) to 2017-09-04 (00:00)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 3 (ReportPDF Icon) R15060 2017-04-24
    Version 4

    2017-09-02 (00:00) to 2017-10-25 (00:00)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 3 (ReportPDF Icon) R15152 2017-09-02
    Version 4 2017-10-26 (00:00) to 

    2018-01-08 (00:00)

    No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 3 (ReportPDF Icon) R15180 2017-10-26
    Version 4 2018-01-09 (00:00) to 2018-03-13 (00:00) No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018. Validated-Stage 3 (ReportPDF Icon) R15181 2018-01-09
    Version 4 2018-03-13 (00:00) to 

    2018-06-03 (00:00)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 3 (ReportPDF Icon) R15182 2018-03-14
    Version 5 2015-03-31 (00:00) to 

    2018-06-13 (00:00)

    Changes to this version include:

    • Level-1B water-corrected brightness temperatures are used in passive soil moisture retrieval. This procedure corrects for anomalous soil moisture values seen near coastlines in the previous version and should result in less rejected data due to waterbody contamination. Five new data fields accommodate this correction: grid_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_uncorrected, and tb_v_uncorrected.
    • Improved depth correction for effective soil temperature used in passive soil moisture retrieval; new results are captured in the surface_temperature data field. This correction reduces the dry bias seen when comparing SMAP data to in situ data from the core validation sites.
    • Frozen ground flag updated to reflect improved freeze/thaw detection algorithm, providing better accuracy; new results are captured in bit 7 of the surface_flag.

    Validated-Stage 3 (ReportPDF Icon) R16000 2018-06-01
    Version 5 2015-03-31 (00:00) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage 3 (ReportPDF Icon) R16010 2018-06-06

    SMAP Enhanced L3 Radiometer Global Daily 9 km EASE-Grid Soil Moisture (SPL3SMP_E)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented

    Version 1

    2015-03-31 (00:00) to 2017-04-22 (23:59)

    First public data release Validated-Stage 3 (ReportPDF Icon) R14010 2016-12-07

    Version 1

    2017-04-23 (00:00) to 2017-09-05 (00:00)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 3 (ReportPDF Icon) R15060 2017-04-24
    Version 1

    2017-09-03 (00:00) to 2017-10-25 (00:00)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 3 (ReportPDF Icon) R15152

    2017-09-03

    Version 1 2017-10-26 (00:00) to 2018-01-08 (00:00) No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 3 (ReportPDF Icon) R15180 2017-10-26
    Version 1

    2018-01-09 (00:00) to 2018-03-13 (00:00)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018.

    Validated-Stage 3 (ReportPDF Icon) R15181 2018-01-09
    Version 1 2018-03-13 (00:00) to 2018-06-03 (00:00) No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 3 (ReportPDF Icon) R15182 2018-03-14
    Version 2 2015-03-31 (00:00) to 

    2018-06-13 (00:00)

    Changes to this version include:

    • Level-1B water-corrected brightness temperatures are used in passive soil moisture retrieval. This procedure corrects for anomalous soil moisture values seen near coastlines in the previous version and should result in less rejected data due to waterbody contamination. Five new data fields accommodate this correction: grid_surface_status, surface_water_fraction_mb_h, surface_water_fraction_mb_v, tb_h_uncorrected, and tb_v_uncorrected.
    • Improved depth correction for effective soil temperature used in passive soil moisture retrieval; new results are captured in the surface_temperature data field. This correction reduces the dry bias seen when comparing SMAP data to in situ data from the core validation sites.
    • Frozen ground flag updated to reflect improved freeze/thaw detection algorithm, providing better accuracy; new results are captured in bit 7 of the surface_flag.

    Validated-Stage 3 (ReportPDF Icon) R16000 2018-06-01
    Version 2 2015-03-31 (00:00) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. Validated-Stage 3 (ReportPDF Icon) R16010 2018-06-06

    SMAP L3 Radar Global Daily 3 km EASE-Grid Soil Moisture (SPL3SMA)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 2
     
    2015-04-25 (00:00) to 2015-07-07 (23:59) First public data release Beta (ReportPDF Icon) R12170 2015-11-03
    Version 2
     
    2015-04-13 (00:00) to 2015-04-24 (23:59)

    This version incorporates a radar calibration update to process data for 13-23 April 2015.

    Beta (ReportPDF Icon) R12240 2016-01-13
    Version 3
     
    2015-04-13 (00:00) to present Changes to this version include:
    • Transitioned to Validated-Stage 1
    • Uses SPL2SMA V3 Validated data as input; inherited all changes and improvements of the new version
    Validated-Stage 1 (ReportPDF Icon) R13080 2016-04-21

    SMAP L3 Radar/Radiometer Global Daily 9 km EASE-Grid Soil Moisture (SPL3SMAP)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 2
     
    2015-04-25 (00:00) to 2015-07-07 (23:59) First public data release Beta (ReportPDF Icon) R12170 2015-11-03
    Version 2
     
    2015-04-13 (00:00) to 2015-04-24 (23:59)

    This version incorporates a radar calibration update to process data for 13-23 April 2015.

    Beta (ReportPDF Icon) R12240 2016-01-13
    Version 2 2015-04-29 (03:58) to 2015-04-29 (04:51) No science change. CRID incremented to coincide with an update to the radiometer reflector table SPL1BTB V2 and SPL1CTB V2. Beta (ReportPDF Icon) R12241 2015-04-29
    Version 3
     
    2015-04-13 (00:00) to present Changes to this version include:
    • Transitioned to Validated-Stage 2
    • Using SPL2SMAP V3 Validated data as input
    Validated-Stage 2 (ReportPDF Icon) R13080

    2016-04-21

    SMAP L3 Radar Northern Hemisphere Daily 3 km EASE-Grid Freeze/Thaw State (SPL3FTA)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 2
     
    2015-04-25 (00:00) to 2015-07-07 (23:59) First public data release Beta (ReportPDF Icon) R12170 2015-11-03
    Version 2
     
    2015-04-13 (00:00) to 2015-04-24 (23:59)

    This version incorporates a radar calibration update to process data for 13-23 April 2015.

    Beta (ReportPDF Icon) R12240 2016-01-13
    Version 3
     
    2015-04-13 (00:00) to 

    2015-07-07 (00:00)

    Changes to this version include:
    • Transitioned to Validated-Stage 2
    • Uses SPL1CS0 V3 Validated data as input
    • Using full swath except for nadir-anomaly flagged areas to provide better coverage
    • Resolved some flag and fillValue errors
    Validated-Stage 2
    (ReportPDF Icon)
    R13080 2016-04-21

    SMAP L3 Radiometer Northern Hemisphere Daily 36 km EASE-Grid Freeze/Thaw State (SPL3FTP)

    Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
    Version 1
     
    2015-03-31 (00:00) to

    2017-04-22 (23:59)

    First public data release Validated-Stage 3 (ReportPDF Icon) R14010 2016-12-07
    Version 1

    2017-04-23 (00:00) to 2017-09-05 (00:00)

    Changes to this version include:
    • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
    • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
    • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
    • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
    Validated-Stage 3 (ReportPDF Icon) R15060 2017-04-24
    Version 1

    2017-09-06 (00:00) to 2017-10-25 (00:00)

    Changes to this version include:
    • Updated compiler optimization flag in radiometer processor to reduce run time
    • Compiled optimization flags
    • Bug fix for initialization error (error surfaced by optimization flags)
    • Note that the data content/quality has not changed
    Validated-Stage 3 (ReportPDF Icon) R15152 2017-09-06
    Version 1 2017-10-26 (00:00) to 2018-01-08 (00:00) No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 3 (ReportPDF Icon) R15180 2017-10-26
    Version 1

    2018-01-09 (00:00) to 2018-03-13 (00:00)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018.

    Validated-Stage 3 (ReportPDF Icon) R15181 2018-01-09
    Version 1 2018-03-13 (00:00) to 

    2018-06-03 (00:00)

    No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 3 (ReportPDF Icon) R15182 2018-03-14
    Version 2 2015-03-31 (00:00) to 2018-06-13 (00:00)

    Changes to this version include:

    • Implementation of a supplementary single-channel V-pol (SCV) algorithm for areas of lower latitudes where the seasonal difference of the NPR algorithm is too small to be effectively used to discriminate freeze/thaw state; results are captured in the retrieval_quality_flag. This change provides stronger flag agreement between Tair and Tsoil, and for ascending/p.m. versus descending/a.m. overpasses due to physics (e.g. the NPR algorithm response to wet snow over frozen soil in spring). It also addresses an artifact of the validation approach (e.g. soils remain thawed for weeks after freeze onset in fall due to insulation from snow).
    • With the addition of the new SCV algorithm to the NPR baseline algorithm, spatial coverage of freeze/thaw data was extended to global. Data are output on a fixed global 36 km EASE-Grid 2.0 and are provided in the Freeze_Thaw_Retrieval_Data_Global group.
    • Updated retrieval_quality_flag for water contamination/permanent ice.
    • Implementation of false flag mitigation using TB screening and AMSR-E weekly climatology maps, resulting in significantly fewer false flags.
    Validated-Stage 3 (ReportPDF Icon) R16000 2018-06-01
    Version 2 2015-03-31 (00:00) to present

    No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. In addition, /Metadata/GridSpatialRepresentation and /Metadata/Extent structures modified to include definitions for both Polar and Global grid metadata parameters.

      Validated-Stage 3 (ReportPDF Icon) R16010 2018-06-06

      SMAP Enhanced L3 Radiometer Northern Hemisphere Daily 9 km EASE-Grid Freeze/Thaw State (SPL3FTP_E)

      Major Version Temporal Coverage Version Changes Maturity State Composite Release ID (CRID) Date Implemented
      Version 1 2015-03-31 (00:00) to 2017-04-23 (23:59) First public data release

      Validated-Stage 3 (ReportPDF Icon)

      R14010 2016-12-07
      Version 1 2017-04-24 (00:00) to

      2017-09-05 (00:00)

      Changes to this version include:
      • Processing capabilities for the upcoming SMAP/Sentinel-1 radiometer/radar soil moisture product
      • SPL1BTB processing change to Atmospheric Correction to ensure proper unit conversion
      • Changes to resolve bugs that were causing SPL1BTB_E processing to fail
      • Note: Temporal coverage for CRID R15060 varies slightly; though the majority of R15060 files begin at 2017-04-24 (11:00), some R15060 files appear earlier in the time series. 
      Validated-Stage 3 (ReportPDF Icon) R15060 2017-04-24
      Version 1

      2017-09-06 (00:00) to 2017-10-25 (00:00)

      Changes to this version include:
      • Updated compiler optimization flag in radiometer processor to reduce run time
      • Compiled optimization flags
      • Bug fix for initialization error (error surfaced by optimization flags)
      • Note that the data content/quality has not changed
      Validated-Stage 3 (ReportPDF Icon) R15152 2017-09-06
      Version 1 2017-10-26 (00:00) to 2018-01-08 (00:00) No science change. CRID incremented to coincide with release of the new SMAP/Sentinel-1 L2 Radiometer/Radar 30-Second Scene 3 km EASE-Grid Soil Moisture (SPL2SMAP_S) product. Validated-Stage 3 (ReportPDF Icon) R15180 2017-10-26
      Version 1

      2018-01-09 (00:00) to 2018-03-13 (00:00)

      No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January and February 2018.

      Validated-Stage 3 (ReportPDF Icon) R15181 2018-01-09
      Version 1 2018-03-13 (00:00) to 2018-06-03 (00:00) No science change. CRID incremented to coincide with an update to the radiometer reflector ancillary file for January through December 2018. Validated-Stage 3 (ReportPDF Icon) R15182 2018-03-14
      Version 2 2015-03-31 (00:00) to 2018-06-13 (00:00)

      Changes to this version include:

      • Implementation of a supplementary single-channel V-pol (SCV) algorithm for areas of lower latitudes where the seasonal difference of the NPR algorithm is too small to be effectively used to discriminate freeze/thaw state; results are captured in the retrieval_quality_flag. This change provides stronger flag agreement between Tair and Tsoil, and for ascending/p.m. versus descending/a.m. overpasses due to physics (e.g. the NPR algorithm response to wet snow over frozen soil in spring). It also addresses an artifact of the validation approach (e.g. soils remain thawed for weeks after freeze onset in fall due to insulation from snow).
      • With the addition of the new SCV algorithm to the NPR baseline algorithm, spatial coverage of freeze/thaw data was extended to global. Data are output on a fixed global 36 km EASE-Grid 2.0 and are provided in the Freeze_Thaw_Retrieval_Data_Global group.
      • Updated retrieval_quality_flag for water contamination/permanent ice.
      • Implementation of false flag mitigation using TB screening and AMSR-E weekly climatology maps, resulting in significantly fewer false flags.
      Validated-Stage 3 (ReportPDF Icon) R16000 2018-06-01
      Version 2 2015-03-31 (00:00) to present No science change. CRID incremented to coincide with updates to L1-L3 radiometer products. In addition, /Metadata/GridSpatialRepresentation and /Metadata/Extent structures modified to include definitions for both Polar and Global grid metadata parameters. Validated-Stage 3 (ReportPDF Icon) R16010 2018-06-06

      SMAP L4 Global 3-hourly 9 km Surface and Rootzone Soil Moisture Analysis Update (SPL4SMAU)

      Major Version Temporal Coverage Version Changes Maturity State Science Version ID Date Implemented
      Version 1
       
      2015-03-31 (01:30) to 2015-10-26 (01:30) First public data release Beta (ReportPDF Icon) Vb1010 2015-10-30
      Version 1
       
      2015-10-26 (01:30) to 2016-04-22 (01:30)

      Input data source changed from SPL1CTB V1 Beta data to SPL1CTB V2 Validated-Stage 1 data.

      Beta (ReportPDF Icon) Vb1012 2015-10-30
      Version 2
       
      2015-03-31 (01:30) to 2016-12-07 (10:31) Changes to this version include:
      • Transitioned to Validated-Stage 2
      • Using updated SPL1CTB V3 Validated data as input
      • Minor bug fixes
      Validated-Stage 2
      (ReportPDF Icon)

      Vv2010

      2016-04-21
      Version 2 2015-03-31 (01:30) to 2017-07-15 (01:30) No science change. CRID incremented to coincide with the release of the following: enhanced products, including SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, SPL3FTP_E (Version 1); SPL3FTP (Version 1); and SPL2SMP, SPL3SMP (Version 4). Validated-Stage 2
      (ReportPDF Icon)
      Vv2030 2016-12-07
      Version 3 2015-03-31 (01:30) to 

      2018-06-04 (22:30)

      Changes to this version include:

      • SMAP observations are now assimilated in Eastern Europe, the Middle East, and East Asia due to expanded coverage of the brightness temperature scaling parameters. The latter are based on two years of SMAP Version 3 brightness temperature observations where the SMOS climatology is unavailable due to RFI.
      • An improved version of the model-only Nature Run (NRv4.1) simulation is used to derive the brightness temperature scaling parameters, the model soil moisture initial conditions, and the soil moisture climatology.
      • Minor bug fixes.
      Validated-Stage 2
      (ReportPDF Icon)
      Vv3030 2017-07-17
      Version 4 2018-06-05 (01:30) to present

      Changes to this version include:

      • The land surface modeling system was revised in the following ways:
        • Improved input parameter data sets for land cover, topography, and vegetation height are based on more recent data sets. Land cover inputs were updated to the GlobCover2009 product, resulting in a slightly different land mask between Version 3 and Version 4. Topographic statistics now rely on observations from the Shuttle Radar Topography Mission. Finally, vegetation height inputs are derived from space-borne lidar measurements.
        • The model background precipitation forcing is rescaled to match the climatology of the Global Precipitation Climatology Project (v2.2), which results in substantial changes in the precipitation and soil moisture climatology in Africa and the high latitudes, where the gauge-based Climate Prediction Center Unified precipitation is not used.
        • SMAP Level-2 soil moisture retrievals and in situ soil moisture measurements from the Soil Climate Analysis Network and U.S. Climate Reference Network were used to calibrate a particular Catchment model parameter that governs the recharge of soil moisture from the model’s root-zone excess reservoir into the surface excess reservoir. Specifically, the replenishment of soil moisture near the surface from below under non-equilibrium conditions was substantially reduced, which brings the model’s surface soil moisture more in line with the SMAP Level-2 and in situ soil moisture.
        • Additional model changes include revisions to the parameters and parameterizations of the surface energy balance and the snow depletion curve.
      • The Version 4 brightness temperature scaling parameters are based on eight years of SMOS observations and three years of SMAP observations where the SMOS climatology is unavailable due to radio frequency interference. Note that the calibration of the assimilated SMAP brightness temperatures changed substantially from Version 3 to Version 4.
      • Analysis increments are no longer computed for the “catchment deficit” model prognostic variable in the Ensemble Kalman filter update step.
      • Minor bug fixes.
      • Added x and y coordinate variables [including arrays of EASE-Grid 2.0 coordinate values, Climate and Forecast (CF)-compliant metadata, and HDF-5 dimension scales] as well as an EASE-Grid 2.0 projection grid mapping variable. This augmentation of L4 soil moisture data files improves interoperability and user workflow via ArcGIS/QGIS, OPeNDAP, and programmatic access. Three new data fields accommodate this change: EASE2_global_projection, x, and y
      Validated-Stage 2
      (ReportPDF Icon)
      Vv4010 2018-06-14
      Version 4 2015-03-31 (01:30) to 2017-01-15 (22:30) Reprocessed data from 2015-03-31 through 2017-01-15 using OASIS Level-1C data as input. OASIS data are processed by the Science Data System (SDS) on the Offline Algorithm Staging and Input System (OASIS). Validated-Stage 2
      (ReportPDF Icon)
      Vv4011 2018-06-14

      SMAP L4 Global 3-hourly 9 km Surface and Rootzone Soil Moisture Geophysical Data (SPL4SMGP)

      Major Version Temporal Coverage Version Changes Maturity State Science Version ID Date Implemented
      Version 1
       
      2015-03-31 (00:00) to 2015-10-26 (00:00) First public data release Beta (ReportPDF Icon) Vv1010 2015-10-30
      Version 1
       
      2015-10-26 (00:00) to 2016-04-22 (00:00)

      Input data source changed from SPL1CTB V1 Beta data to SPL1CTB V2 Validated-Stage 1 data.

      Beta (ReportPDF Icon) Vv1012 2015-10-30
      Version 2
       
      2015-03-31 (00:00) to 2016-12-07 (10:31) Changes to this version include:
      • Transitioned to Validated-Stage 2
      • Using updated SPL1CTB V3 Validated data as input
      • Minor bug fixes
      Validated-Stage 2
      (ReportPDF Icon)
      Vv2010 2016-04-21
      Version 2 2015-03-31 (00:00) to 2017-07-15 (00:00)

      No science change. CRID incremented to coincide with the release of the following: enhanced products, including SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, SPL3FTP_E (Version 1); SPL3FTP (Version 1); and SPL2SMP, SPL3SMP (Version 4).

      Validated-Stage 2
      (ReportPDF Icon)

      Vv2030

      2016-12-07

      Version 3

      2015-03-31 (00:00) to 2018-06-04 (21:00)

      Changes to this version include:

      • SMAP observations are now assimilated in Eastern Europe, the Middle East, and East Asia due to expanded coverage of the brightness temperature scaling parameters. The latter are based on two years of SMAP Version 3 brightness temperature observations where the SMOS climatology is unavailable due to RFI.
      • An improved version of the model-only Nature Run (NRv4.1) simulation is used to derive the brightness temperature scaling parameters, the model soil moisture initial conditions, and the soil moisture climatology.
      • Minor bug fixes.
      Validated-Stage 2
      (ReportPDF Icon)
      Vv3030 2017-07-17
      Version 4 2018-06-05 (00:00) to present

      Changes to this version include:

      • The land surface modeling system was revised in the following ways:
        • Improved input parameter data sets for land cover, topography, and vegetation height are based on more recent data sets. Land cover inputs were updated to the GlobCover2009 product, resulting in a slightly different land mask between Version 3 and Version 4. Topographic statistics now rely on observations from the Shuttle Radar Topography Mission. Finally, vegetation height inputs are derived from space-borne lidar measurements.
        • The model background precipitation forcing is rescaled to match the climatology of the Global Precipitation Climatology Project (v2.2), which results in substantial changes in the precipitation and soil moisture climatology in Africa and the high latitudes, where the gauge-based Climate Prediction Center Unified precipitation is not used.
        • SMAP Level-2 soil moisture retrievals and in situ soil moisture measurements from the Soil Climate Analysis Network and U.S. Climate Reference Network were used to calibrate a particular Catchment model parameter that governs the recharge of soil moisture from the model’s root-zone excess reservoir into the surface excess reservoir. Specifically, the replenishment of soil moisture near the surface from below under non-equilibrium conditions was substantially reduced, which brings the model’s surface soil moisture more in line with the SMAP Level-2 and in situ soil moisture.
        • Additional model changes include revisions to the parameters and parameterizations of the surface energy balance and the snow depletion curve.
      • The Version 4 brightness temperature scaling parameters are based on eight years of SMOS observations and three years of SMAP observations where the SMOS climatology is unavailable due to radio frequency interference. Note that the calibration of the assimilated SMAP brightness temperatures changed substantially from Version 3 to Version 4.
      • Analysis increments are no longer computed for the “catchment deficit” model prognostic variable in the Ensemble Kalman filter update step.
      • Minor bug fixes.
      • Added x and y coordinate variables [including arrays of EASE-Grid 2.0 coordinate values, Climate and Forecast (CF)-compliant metadata, and HDF-5 dimension scales] as well as an EASE-Grid 2.0 projection grid mapping variable. This augmentation of L4 soil moisture data files improves interoperability and user workflow via ArcGIS/QGIS, OPeNDAP, and programmatic access. Three new data fields accommodate this change: EASE2_global_projection, x, and y.
      Validated-Stage 2
      (ReportPDF Icon)
      Vv4010 2018-06-14
      Version 4 2015-03-21 (00:00) to 2017-01-15 (00:00) Reprocessed data from 2015-03-31 through 2017-01-15 using OASIS Level-1C data as input. OASIS data are processed by the Science Data System (SDS) on the Offline Algorithm Staging and Input System (OASIS). Validated-Stage 2
      (ReportPDF Icon)
      Vv4011 2018-06-14

      SMAP L4 Global 9 km Surface and Rootzone Soil Moisture Land Model Constants (SPL4SMLM)

      Major Version Temporal Coverage Version Changes Maturity State Science Version ID Date Implemented
      Version 1
       
      2015-04-01 (00:00) to present (time-invariant) First public data release Beta (ReportPDF Icon) Vb1010 2015-10-30
      Version 1
       
      2015-10-26 (00:00) to present (time-invariant)

      Input data source changed from SPL1CTB V1 Beta data to SPL1CTB V2 Validated-Stage 1 data.

      Beta (ReportPDF Icon) Vb1012 2015-10-30
      Version 2
       
      2015-03-31 (00:00) to present (time-invariant) Updated to coincide changes to SPL4SMAU V1 and SPL4SMGP V1.  Validated-Stage 2
      (ReportPDF Icon)
      Vv2010 2016-04-21
      Version 2 2015-03-31 (00:00) to present (time-invariant) No science change. CRID incremented to coincide with the release of the following: enhanced products, including SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, SPL3FTP_E (Version 1); SPL3FTP (Version 1); and SPL2SMP, SPL3SMP (Version 4). Validated-Stage 2
      (ReportPDF Icon)
      Vv2030 2016-12-07
      Version 3 2015-03-31 (00:00) to present (time-invariant)

      Changes to this version include:

      • SMAP observations are now assimilated in Eastern Europe, the Middle East, and East Asia due to expanded coverage of the brightness temperature scaling parameters. The latter are based on two years of SMAP Version 3 brightness temperature observations where the SMOS climatology is unavailable due to RFI.
      • An improved version of the model-only Nature Run (NRv4.1) simulation is used to derive the brightness temperature scaling parameters, the model soil moisture initial conditions, and the soil moisture climatology.
      • Minor bug fixes.
      Validated-Stage 2
      (ReportPDF Icon)
      Vv3030 2017-07-17
      Version 4 2015-03-31 (00:00) to present (time-invariant)

      Changes to this version include:

      • The land surface modeling system was revised in the following ways:
        • Improved input parameter data sets for land cover, topography, and vegetation height are based on more recent data sets. Land cover inputs were updated to the GlobCover2009 product, resulting in a slightly different land mask between Version 3 and Version 4. Topographic statistics now rely on observations from the Shuttle Radar Topography Mission. Finally, vegetation height inputs are derived from space-borne lidar measurements.
        • The model background precipitation forcing is rescaled to match the climatology of the Global Precipitation Climatology Project (v2.2), which results in substantial changes in the precipitation and soil moisture climatology in Africa and the high latitudes, where the gauge-based Climate Prediction Center Unified precipitation is not used.
        • SMAP Level-2 soil moisture retrievals and in situ soil moisture measurements from the Soil Climate Analysis Network and U.S. Climate Reference Network were used to calibrate a particular Catchment model parameter that governs the recharge of soil moisture from the model’s root-zone excess reservoir into the surface excess reservoir. Specifically, the replenishment of soil moisture near the surface from below under non-equilibrium conditions was substantially reduced, which brings the model’s surface soil moisture more in line with the SMAP Level-2 and in situ soil moisture.
        • Additional model changes include revisions to the parameters and parameterizations of the surface energy balance and the snow depletion curve.
      • The Version 4 brightness temperature scaling parameters are based on eight years of SMOS observations and three years of SMAP observations where the SMOS climatology is unavailable due to radio frequency interference. Note that the calibration of the assimilated SMAP brightness temperatures changed substantially from Version 3 to Version 4.
      • Analysis increments are no longer computed for the “catchment deficit” model prognostic variable in the Ensemble Kalman filter update step.
      • Minor bug fixes.
      • Added x and y coordinate variables [including arrays of EASE-Grid 2.0 coordinate values, Climate and Forecast (CF)-compliant metadata, and HDF-5 dimension scales] as well as an EASE-Grid 2.0 projection grid mapping variable. This augmentation of L4 soil moisture data files improves interoperability and user workflow via ArcGIS/QGIS, OPeNDAP, and programmatic access. Three new data fields accommodate this change: EASE2_global_projection, x, and y.
      Validated-Stage 2
      (ReportPDF Icon)
      Vv4010 2018-06-14

      SMAP L4 Global Daily 9 km Carbon Net Ecosystem Exchange (SPL4CMDL)

      Major Version Temporal Coverage Version Changes Maturity State Science Version ID Date Implemented
      Version 1 2015-04-13 (00:00) to 2016-04-21 (23:59) First public data release Beta (ReportPDF Icon) Vb1010 2015-10-30
      Version 2
       
      2015-03-31 (00:00) to 2016-01-16 (23:59)

      Changes to this version include:

      • Transitioned to Validated-Stage 2
      • Using SPL4SMAU V2 Validated and SPL4SMGP V2 Validated data as input
      • Update to process radiometer data from 2015-03-31 to 2015-04-12
      • Some data fields renamed from *_av to *_mean
      • Updated to have have continuous RMSE-based "quality" fields instead of the categorical quality flag in V1
      Validated-Stage 2
      (ReportPDF Icon)
      Vv2010 2016-04-21
      Version 2 2015-03-31 (00:00) to 2016-03-29 (23:59) No science change. CRID incremented to coincide with the release of the following: enhanced products, including SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, SPL3FTP_E (Version 1); SPL3FTP (Version 1); and SPL2SMP, SPL3SMP (Version 4). Validated-Stage 2
      (ReportPDF Icon)
      Vv2040 2016-12-07
      Version 2 2015-03-31 (00:00) to 2017-07-11 (23:59) Change involves modification to the L4C preprocessor to allow for ingest of MODIS Collection 6 fPAR inputs in response to planned termination of the MODIS Collection 5 stream from the LPDAAC. Validated-Stage 2
      (ReportPDF Icon)
      Vv2043 2017-03-30
      Version 3 2015-03-31 (00:00) to 

      2018-06-04 (00:00)

      Changes to this version include:

      • Uses dynamic 8-day fPAR inputs obtained from the latest (Collection 6) MODIS fPAR record at 500 m resolution. The preprocessor was updated to handle the finer resolution MODIS Collection 6 inputs, which are interpolated to 1 km resolution prior to model processing. The prior (Version 2) processor used MODIS Collection 5 fPAR inputs, which were derived at 1 km resolution.
      • Updated the ancillary MODIS fPAR 8-day climatology used for fPAR gap-filling as an L4C model preprocessing step to reflect new MODIS Collection 6 fPAR inputs. The fPAR climatology is derived from a longer 14-year (2000-2014) MODIS record relative to the original 12-year (2000-2012) Collection 5 fPAR record used in Version 2 processing.
      • For each grid cell, a sine-curve-based seasonal fPAR climatology curve is now used to identify and screen anomalous 8-day fPAR variations in the preprocessor. This change reduces impacts of anomalous fPAR temporal variations that may not be captured by the MODIS fPAR product quality control (QC) flags, particularly during seasonal transitions at northern latitudes.
      • Updated and recalibrated the ancillary Biome Properties Look-Up Table (BPLUT) and re-initialized the model initial global soil organic carbon (SOC) pools to reflect new MODIS Collection 6 fPAR inputs. The BPLUT calibration was conducted using global historical FLUXNET in situ tower eddy covariance CO2 flux measurement records for representative global land cover types using a similar step-wise calibration procedure employed for the Version 2 product.
      • A minor bug fix to the post-processor was made to ensure that all grid cell no-data fill values are identified with a consistent -9999 notation; the prior Version 2 product erroneously assigned some no-data values as -999900.
      Validated-Stage 2
      (ReportPDF Icon)
      Vv3040 2017-07-17
      Version 4 2015-03-31 (00:00) to present

      Changes to this version largely affect model inputs and ancillary files rather than changes to the internal model structure or code. Note that Version 4 is slightly better than Version 3 in RMSE terms, with improvement generally larger for drier sites. Specific changes include:

      • The carbon model biome properties lookup table (BPLUT) has been calibrated using an augmented FLUXNET global tower site record which includes more calibration sites (335 sites compared to 228 sites for V3), expanded tower data records extending to at least 2015, and the addition of new tower sites representing more land cover types.
      • Revised Level-4 carbon global model calibration and SOC initialization using an extended (2000-2017) MODIS fPAR (V006) record and the latest SMAP Nature Run (NRv7.2) climate data records.
      • Implemented minor changes to spatial weighting of calibration tower sites within a model grid cell and reduced the outlier influence on model response curve fitting.
      Validated-Stage 2
      (ReportPDF Icon)
      Vv4020 2018-06-14

      Naming Conventions

      Major Version

      Major versions indicate the Series- or Collection-level major version of SMAP data products. Major versions signify that one or more changes have been made that caused a scientific change in the data, including:

      • Change of input data used
      • Change to algorithm or processing software
      • Significant change to file-level metadata

      Major version changes typically result in a reprocessing of the entire time series. As shown in Figure 1, the major version ID is located in SMAP HDF5 (.h5) data files within the DatasetIdentification group.

      Figure 1. Major Versions of SMAP Data Products
      To find the major version of a SMAP data product, navigate to DatasetIdentification within the Metadata group of any SMAP HDF5 (.h5) data file. The ECSVersionID = 004 indicates that these are Version 4 data.

      Composite Release IDs (CRIDs)

      SMAP Level-1 through Level-3 data file names include a Composite Release ID (CRID) that represents changes to any data processing condition that might impact SMAP products. The CRID incorporates algorithm, software, and other parameters involved in data processing. Note: The major version does not necessarily coincide with the CRID major version.

      Files are named according to the following convention, with the CRID shown in bold:

      SMAP_L1A_RADIOMETER_[Orbit#]_[A/D]_yyyymmddThhmmss_RLVvvv_NNN.[ext]

      Where:

      Variable Description
      R Release
      L Launch Indicator (1: SMAP Standard Data)
      V 1-Digit CRID Major Version Number
      vvv 3-Digit CRID Minor Version Number

      Science Version IDs

      SMAP Level-4 data file names include a Science Version ID that, like the Composite Release ID for Level-1 through -3 data, represents changes to any data processing condition that might impact SMAP product results.

      Files are named similar to the following convention, with the Science Version ID shown in bold:

      SMAP_L4_C_MDL_yyyymmddThhmmss_VLMmmm_NNN.[ext]

      Where:

      Variable Description
      V Science Version
      L Launch Indicator (b: Beta-quality data, v: Validated data)
      M 1-Digit Major Science Version Number
      mmm 3-Digit Minor Science Version Number

      Maturity States

      • Beta — Indicates data sets using a developing algorithm with updates anticipated.
      • Validated — Data sets are upgraded to Validated once the Beta algorithm is verified by the algorithm team and validated by the validation team.

      Validation Stages

      Additionally, a stage (1, 2, or 3) may be appended to Validated product maturity codes. The following table describes the validation stages.

      Validation Stage Description
      Stage 1 Product accuracy is estimated using a small number of independent measurements obtained from selected locations, time periods, and ground-truth/field program efforts.
      Stage 2 Product accuracy is assessed over a widely distributed set of locations and time periods via several ground-truth and validation efforts.
      Stage 3 Product accuracy is assessed, and the uncertainties in the product are well established via independent measurements made in a systematic and statistically robust way that represents global conditions.

      Temporal Coverage

      Dates

      All dates on this page are listed as four-digit year followed by two-digit month and two-digit day, such as 2015-12-31.

      Times

      Times are listed as two-digit hour followed by two-digit minute , such as 17:24. Times are in Coordinated Universal Time (UTC), which is also known as Greenwich Mean Time (GMT) and/or "Z" or "Zulu Time."